This wraps geosphere::distGeo and allows unit conversion. It is suitable
for use in dplyr::mutate. The vector lengths must be able to be recycled.
Preferrably the refenrece coordinates are each of length one or the same
length as the test coordinates.
Usage
geographic_distance(lat, long, lat_ref, long_ref, unit = c("miles", "km"))
Arguments
- lat
A vector of latitude coordinates.
- long
A vector of longitude coordinates.
- lat_ref
A reference latitude. May be a vector.
- long_ref
A reference longitude. May be a vector.
- unit
The output unit, default is miles. Must be miles or kilometers
(km). The conversion factor is 1609.334 meters to 1 mile.
Value
A vector of the distance between two points on a globe. Any missing
coordinates will return NA.
Examples
coords <- c(36.68, -108.82) # somewhere in New Mexico
ref <- c(45, -100) # somewhere in South Dakota
if (FALSE) geographic_distance(coords[1], coords[2], ref[1], ref[2]) # \dontrun{}
